2017: The Year in Volcanic Activity

While this has been a relatively average year for the world's active volcanoes, the activity that did take place was spectacular. Out of an estimated 1,500 active volcanoes, 50 or so erupt every year, spewing steam, ash, toxic gases, and lava. In 2017, erupting volcanoes included Shiveluch in Russia, Villarrica in Chile, Mount Sinabung and Mount Agung in Indonesia, Turrialba in Costa Rica, Piton de la Fournaise on Réunion Island, Kilauea on Hawaii, Popocatepetl and Volcán de Colima in Mexico, Bogoslof Volcano in Alaska, Manaro Voui in Vanuatu, Mount Etna in Sicily, and more. Collected below are scenes from the wide variety of volcanic activity on Earth over the past year.

An Indonesian woman watches an eruption of Mount Sinabung from Tiga Pancur village, in Karo in North Sumatra on November 3, 2017. Sinabung roared back to life in 2010 for the first time in 400 years. After another period of inactivity it erupted once more in 2013, and has remained highly active since.#

A long-time exposure shows a lightning storm and the reddish glow of molten lava, which flows from the Piton de la Fournaise, one of the world's most active volcanoes, on the French Indian Ocean Réunion Island on February 3, 2017.#

On May 28, 2017, Bogoslof volcano, a submarine stratovolcano in the Aleutian Islands that just barely pokes its summit above sea level, was captured by a passing satellite as it erupted. This Worldview satellite image collected on May 28 shows the initial development of the eruption cloud. The eruption began about 18 minutes prior to this image and the cloud rose to an altitude in excess of 40,000 ft above sea level. The white color of the cloud is due to the large amount of water that is incorporated into the eruption column as the vent is located in shallow water. Bogoslof erupted numerous times throughout the early months of 2017.#

A closer look at the Worldview satellite image of the May 28th Bogoslof eruption. Note the explosive activity at the base, called "tephra jets." These are common where extremely hot volcanic material and gas meet water, converting explosively into particle-filled clouds of steam.#

The Himawari 8 weather satellite also happened to have Alaska's Bogoslof volcano in view during its May 28 eruption, capturing this sequence of images as the ash cloud reached more than 40,000 feet above sea level, then spread out on the winds.#

A tourist looks at the ash spewed out by the Turrialba volcano in Cartago, Costa Rica, on January 6, 2017. Costa Rican authorities declared a green alert in the entire metropolitan area around the capital.#

An open lava stream pours out of a lava-tube exit, approximately 70 feet up on a sea cliff, falling into the ocean below, on January 28, 2017. Lava flowing from Kilauea began entering the sea in this location at the start of the year, intensifying into a "fire hose" of airborne lava. The flow subsided after a collapse on February 2.#

Hawaiian Volcano Observatory geologists observed a breakout from an inflating tumulus on the slopes of Kīlauea on December 6, 2017. As pāhoehoe lava flowed from the tumulus, it cooled and crusted over. But this crust could not contain the amount of lava being supplied to the flow, and molten lava subsequently broke through it.#

Coastal breakouts from Kīlauea on October 4, 2017. Over the previous weeks, there were at least three breakouts within 100 meters (330 feet) of the Kamokuna ocean entry. These lava cascades consisted of both ‘a‘ā and pāhoehoe flows onto the delta. This image was taken by a time-lapse camera of multiple lava cascades on the sea cliff on October 4. Just a few of the many resulting surface flows can be seen on the delta both below the cliff and near the front, which is lit by lava and moonlight.#

Numerous fumaroles are present near the rim of Kilauea's Halema'uma'u Crater, evident by the bright yellow sulfur deposits. In recent years these fumaroles have been covered by a thick carpet of "Pele's hair" (glassy strands of cooled lava) produced by the lava lake. Moisture emitted by the fumaroles collects as tiny water droplets on the fine hairs, resembling a thin dusting of snow, photographed here, on May 28, 2017.#

Ash spews from the Popocatepetl volcano as seen from Tepehitec community in Tlaxcala State, Mexico, on November 10, 2017. The Popocatepetl volcano, located about 55 kilometers from Mexico City, has been recording numerous low-intensity eruptions since late September.#

Steam and ash emanates from the Manaro Voui volcano located on Vanuatu's northern island Ambae in the South Pacific, on October 1, 2017. A sudden increase in eruptions in September led officials to raise alarms for island residents, with nearly all evacuated by mid-October. The Vanuatu Daily Post reported that local chiefs made a trek to the shores of Lake Voui for a ceremony and offering to the custodian of Lake Voui: "A highly valued animal (pig) was slaughtered in line with custom. Chief Tari One uttered a custom address at the shore of Lake Voui before the ingredients complete with meat, food, and mats were offered by being released into the lake."#

Clouds of ash from Mount Agung are lit with warm sunset light in Karangasem, Bali, Indonesia, on November 30, 2017. Authorities told tens of thousands of people to leave an area extending 10 kilometers (6 miles) from the volcano as it belched volcanic materials into the air.#